<!DOCTYPE html>
<html>
<head>
	<meta http-equiv="Content-Type" content="text/html">
	<meta charset="utf-8" />
	<meta http-equiv="X-UA-Compatible" content="IE=edge" />
	<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1,maximum-scale=1,user-scalable=no" />
	<title></title>
</head>
<body erke-hide>
</body>
<script>
/**
 * @param {character[]} letters
 * @param {character} target
 * @return {character}
 */
var nextGreatestLetter = function(letters, target) {
    var len=letters.length;
    letters.push(target);
    letters=letters.sort();
    var res=aAronDie(letters,target);
    if(len!=res){
    	return letters[res+1];
    }else{
    	return letters[0];
    };
};
function aAronDie(arr,str){
	var on=0;
	for(var i=0;i<arr.length;i++){
		if(arr[i]==str){
			on=i;
		};
	};
	return on;
};
var res=new nextGreatestLetter(["c", "f", "j"],"z");
</script>
</html>